📚 Part of the TILA-278 Regulatory Dossier — Reader's Guide. This article shows the live document; edits to the source appear here automatically.

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Module 3 — Stability Summary (TILA-278)

Field	Value
Document ID	M3-STAB
Version	1.0
Compound	TILA-278 (anti-TL1A antagonist / IL-22R agonist bispecific)
Standard	ICH Q1A-E / Q5C
Confidentiality	Confidential

Chemistry, manufacturing and controls document for TILA-278.

Change History

Version	Date	Author	Summary
1.0	2026-07-08	CMC/Quality	Initial issue

3.2.S.7 / 3.2.P.8 Stability — Summary of Drug Substance and Drug Product (TILA-278)

1. Introduction and Scope

This section summarizes the stability of the TILA-278 drug substance (DS) and drug product (DP) and provides the data-based justification for the proposed storage conditions, retest/shelf-life periods, in-use conditions, and labelling. TILA-278 is a recombinant humanized IgG1 bispecific monoclonal antibody expressed in a Chinese hamster ovary (CHO) cell line. One Fab arm is an anti-TL1A (TNFSF15) antagonist; the second arm is an interleukin-22 receptor (IL-22R) agonist. The molecule is developed by Virtual Biopharma Inc. for subcutaneous (SC) administration in moderate-to-severe ulcerative colitis (UC).

The DS is a purified, frozen antibody solution. The DP is a sterile, preservative-free aqueous solution for SC injection, presented as a single-use, ready-to-use 1.0 mL prefilled syringe (PFS) and as the same primary syringe assembled into a single-use autoinjector (AI). No reconstitution or dilution is required prior to administration.

This summary integrates results from the drug-substance stability program (3.2.S.7.1–7.3) and the drug-product stability program (3.2.P.8.1–8.3). Detailed protocols, per-batch data tables, and analytical validation reports are provided in the referenced supporting sections. Batches manufactured for the Phase 2b induction study (Protocol TILA278-201) were produced by the same platform process and are representative of, or bracketed by, the primary stability batches described here; their stability behaviour is consistent with the data below.

Data cutoff for this summary: 30 June 2026.

2. Regulatory Basis and Stability Strategy

The stability program is designed and evaluated in accordance with:

• ICH Q1A(R2) — Stability testing of new drug substances and products
• ICH Q1B — Photostability testing (Option 2 exposure)
• ICH Q1C — Stability testing for new dosage forms
• ICH Q1D — Bracketing and matrixing designs
• ICH Q1E — Evaluation of stability data
• ICH Q5C — Stability testing of biotechnological/biological products
• ICH Q6B — Specifications for biotechnological/biological products

The product is intended for global registration covering ICH climatic Zones I–IV. Because both DS and DP are stored refrigerated or frozen (kinetic, not moisture-driven degradation), storage conditions are defined by temperature; relative humidity is controlled only for the accelerated/stress DP arms per Q1A(R2) and is not stability-limiting for a closed, aqueous parenteral in a water-vapour-impermeable glass/elastomer container.

Storage conditions applied:

Study arm	Drug substance	Drug product
Long-term	≤ −40 °C	5 °C ± 3 °C
Accelerated	5 °C ± 3 °C; 25 °C ± 2 °C	25 °C ± 2 °C / 60% ± 5% RH
Stress	40 °C ± 2 °C	40 °C ± 2 °C / 75% ± 5% RH
Photostability	ICH Q1B Option 2	ICH Q1B Option 2

Per ICH Q1B Option 2, samples were exposed to not less than 1.2 million lux·hours of cool-white fluorescent light and not less than 200 W·h/m² of near-UV, with light-protected (foil-wrapped) dark controls run in parallel.

Bracketing (ICH Q1D) is applied to the two DP presentations: the PFS and the AI share an identical primary container (the same Type I borosilicate glass syringe, staked stainless-steel needle, elastomeric plunger stopper, and rigid needle shield). The syringe is placed on stability directly; the AI adds only an external mechanical assembly that does not contact the formulation. Full chemical/biological stability is therefore generated on the PFS and applied to the AI, with device-specific functional stability generated separately on the assembled AI (Section 5.9).

Pre-defined "significant change" criteria (Q5C; applied to accelerated/stress arms):

• Any parameter failing its shelf-life acceptance criterion;
• ≥ 5% absolute change in monomer content (SE-HPLC) from the initial value;
• ≥ 5% change in relative potency (either bioassay) from the initial value, or a result outside 80–125%;
• Appearance no longer conforming, or a > 10% change in sub-visible particle counts trending toward the limit;
• pH change > 0.3 units from the initial value.

3. Stability-Indicating Analytical Procedures

TILA-278 is monitored by an orthogonal panel of methods (validated per ICH Q2(R1); details in 3.2.S.4.3 and 3.2.P.5.3) selected to detect the physicochemical and functional degradation pathways relevant to a bispecific IgG1: aggregation/fragmentation, charge-variant formation (deamidation, C-terminal lysine, isomerization), oxidation, and loss of either binding function. Potency is measured by two independent, mechanism-of-action–reflective cell-based bioassays — one for each arm — so that loss of activity of either binding domain is detectable.

The stability-indicating capability of the panel is established by the forced-degradation studies in Section 4.4, in which each stress condition produces a distinct, method-detectable degradation fingerprint with maintenance of mass balance.

Quality attribute	Method	Stability-indicating	Attribute class
Appearance (colour/clarity/visible particulates)	Visual, Ph. Eur. 2.2.1/2.2.2, USP <790>	Yes	General
pH	Potentiometry	Yes	General
Protein concentration	UV A280	No (content)	General
Osmolality	Freezing-point depression	No	General
Aggregates / monomer / fragments (HMW/LMW)	SE-HPLC	Yes	Purity/impurity
Fragmentation & size purity	CE-SDS (reduced and non-reduced)	Yes	Purity/impurity
Charge variants (acidic/main/basic)	icIEF	Yes	Purity/impurity
Sub-visible particles (≥ 2, ≥ 10, ≥ 25 µm)	Light obscuration, USP <788>; MFI (supportive)	Yes	Purity/impurity
Anti-TL1A neutralization potency	Cell-based reporter bioassay	Yes	Potency
IL-22R agonism potency	Cell-based reporter bioassay	Yes	Potency
Binding (TL1A and IL-22R)	SPR / ligand-binding (supportive)	Yes	Identity/activity
Polysorbate 80 content	HPLC-ELSD / mixed-micelle assay	Yes	Excipient
Container-closure integrity	High-voltage leak / headspace	Yes	Microbiological
Sterility	Ph. Eur. 2.6.1 / USP <71>	—	Microbiological
Bacterial endotoxins	Kinetic LAL, USP <85>	—	Safety
Extractable/deliverable volume	Gravimetric, USP <697>/<1>	No	Delivery

Only a stability-indicating subset (appearance, pH, SE-HPLC, CE-SDS, icIEF, both potency assays, sub-visible particles, PS80, CCIT) is included at each pull point; sterility and endotoxin are tested at start and end (and at the assigned shelf-life point) per Q5C, with CCIT used as a surrogate for microbiological integrity at intermediate points.

4. Drug Substance Stability (3.2.S.7)

4.1 Stability protocol and study design (3.2.S.7.1)

The DS is a purified bispecific IgG1 at a nominal concentration of 150 mg/mL in a histidine-based buffer with polysorbate 80, filled into single-use, closed bioprocess containers (bottles/bags) and stored frozen at ≤ −40 °C. The proposed DS storage condition is ≤ −40 °C.

The primary DS stability protocol comprises long-term (≤ −40 °C), accelerated (5 °C ± 3 °C and 25 °C ± 2 °C), and stress (40 °C ± 2 °C) arms. Long-term pull points are 0, 3, 6, 9, 12, 18, 24, and 36 months, continuing through the proposed retest period; accelerated points are 0, 1, 3, 6, 9, and 12 months; stress points are 0, 2, and 4 weeks and 1 and 3 months. Freeze-thaw cycling and agitation studies support in-process handling and shipping (Section 4.5).

4.2 Primary stability batches

Three primary DS batches (DS-2401, DS-2402, DS-2403) were manufactured at commercial scale by the process described in 3.2.S.2 and placed on stability in Q1 2024. The batches are representative of the commercial process and the material used to manufacture clinical DP for TILA278-201.

4.3 Long-term and accelerated results

At the proposed storage condition (≤ −40 °C), all measured attributes for the three primary batches remain within acceptance criteria through the current 24-month time point, with no meaningful trends. Representative long-term data (mean of three batches) are shown below.

Table 4.3-1. DS long-term stability at ≤ −40 °C (mean of DS-2401/02/03)

Attribute (acceptance)	0 m	6 m	12 m	18 m	24 m
Appearance	Conforms	Conforms	Conforms	Conforms	Conforms
pH (5.5–6.1)	5.8	5.8	5.8	5.8	5.8
Monomer, SE-HPLC (≥ 95.0%)	99.0	99.0	98.9	98.9	98.8
HMW, SE-HPLC (≤ 3.0%)	0.8	0.8	0.9	0.9	1.0
CE-SDS NR purity (≥ 95.0%)	97.0	97.0	96.9	96.8	96.8
icIEF main (report)	69	69	68	68	67
icIEF acidic (report)	21	21	22	22	23
Anti-TL1A potency (80–125%)	101	101	100	100	99
IL-22R potency (80–125%)	100	100	100	99	99

Under accelerated conditions the DS is robust. At 5 °C ± 3 °C, no significant change is observed through 12 months, supporting refrigerated hold and thaw/pool operations. At 25 °C, minor increases in HMW (SE-HPLC) and acidic charge variants (icIEF) appear by 3–6 months without loss of potency below acceptance, supporting extended room-temperature processing excursions.

4.4 Stress and forced degradation

Forced-degradation studies confirm that the analytical panel is stability-indicating and map the principal degradation pathways of the bispecific. Each condition produces a characteristic, orthogonally detectable fingerprint; mass balance was maintained across SE-HPLC, CE-SDS, and icIEF.

Table 4.4-1. DS forced-degradation summary

Stress	Condition	Primary degradation detected	Method(s) responding	Potency impact
Thermal	40 °C, up to 4 weeks	↑ HMW aggregate; ↑ acidic variants	SE-HPLC, icIEF	Both bioassays decline; anti-TL1A more sensitive
Oxidative	0.1% H₂O₂, 24 h	Met/Trp oxidation; ↑ acidic variants	icIEF, peptide map, potency	IL-22R agonism reduced
Low pH	pH 3.5, 25 °C	↑ LMW fragments	CE-SDS(R), SE-HPLC	Both reduced
High pH	pH 9.0, 25 °C	Deamidation; ↑ acidic variants	icIEF, peptide map	Modest decline
Photolytic	ICH Q1B Option 2	Oxidation; ↑ HMW; ↑ acidic variants	icIEF, SE-HPLC, potency	Both reduced
Freeze-thaw (uncontrolled)	10 rapid cycles	↑ HMW; ↑ sub-visible particles	SE-HPLC, light obscuration	Minor

Aggregation (SE-HPLC/CE-SDS) and charge heterogeneity (icIEF) are the most sensitive stability indicators; loss of anti-TL1A neutralization and IL-22R agonism track with these physicochemical changes, confirming that the dual-potency strategy captures functional degradation of both arms.

4.5 Freeze-thaw and agitation

Controlled freeze-thaw studies at the intended container scale demonstrate that the DS tolerates at least five controlled freeze/thaw cycles between ≤ −40 °C and 5 °C with no significant change in aggregation, fragmentation, charge variants, sub-visible particles, or potency. Agitation studies (orbital and shipping-profile) with polysorbate 80 present show no significant increase in HMW or sub-visible particles, supporting the formulation's protection against interfacial stress during handling and transport.

4.6 DS storage statement and retest period

Based on the long-term data at ≤ −40 °C, which show no significant trend in any attribute, a retest period of 36 months at ≤ −40 °C is proposed for the DS. The claim is currently supported by 24 months of real-time data on three commercial-scale batches; the study continues to 36 months under the post-approval protocol (Section 4.7). The DS must not be stored above the labelled frozen condition other than during defined, data-supported processing excursions.

4.7 Post-approval stability commitment (3.2.S.7.2 / 3.2.S.7.3)

Virtual Biopharma Inc. commits to complete the long-term study on the three primary batches to 36 months and to place the first three commercial-scale DS batches manufactured after approval into the long-term (≤ −40 °C) program per the same protocol (one batch per year thereafter). Any confirmed out-of-specification or adverse trend will be reported to the agency per regional requirements.

5. Drug Product Stability (3.2.P.8)

5.1 Stability protocol and study design (3.2.P.8.1)

The DP is a sterile solution at 100 mg/mL TILA-278 in histidine buffer (pH 5.8) with polysorbate 80 and a tonicity agent, filled to a deliverable volume of 1.0 mL (100 mg/dose) in a 1.0 mL long Type I glass staked-needle syringe with an elastomeric plunger and rigid needle shield. The syringe is the primary container for both the PFS and the AI presentations.

The DP is stored upright and inverted (to challenge the elastomeric closure and headspace) under long-term, accelerated, stress, and photostability arms per Section 2. Long-term pull points are 0, 3, 6, 9, 12, 18, and 24 months (continuing per protocol); accelerated points are 0, 1, 3, and 6 months; stress points are 0, 2, and 4 weeks and 1, 2, and 3 months. Sterility and CCIT confirm microbiological integrity is maintained.

5.2 Primary stability batches

Three primary DP batches (DP-2401, DP-2402, DP-2403), filled from DS-2401/02/03 respectively at commercial fill-finish scale, were placed on stability in Q2 2024. They are representative of the commercial process and container-closure and bracket the clinical DP used in TILA278-201.

5.3 Long-term results (5 °C ± 3 °C)

The DP is stable under long-term refrigerated storage. Across the three batches, monomer content, size and charge purity, and both potency values remain within shelf-life acceptance criteria through 24 months, with only small, well-characterized increases in HMW species (SE-HPLC) and acidic charge variants (icIEF) and a correspondingly minor decline in relative potency that remains comfortably within 80–125%. No significant change (as defined in Section 2) occurs at the long-term condition.

Table 5.3-1. DP long-term stability at 5 °C ± 3 °C (mean of DP-2401/02/03)

Attribute (shelf-life acceptance)	0 m	3 m	6 m	9 m	12 m	18 m	24 m
Appearance¹	C	C	C	C	C	C	C
pH (5.5–6.1)	5.8	5.8	5.8	5.8	5.8	5.8	5.8
Concentration (90–110 mg/mL)	100	100	100	100	99	99	99
Monomer, SE-HPLC (≥ 95.0%)	98.6	98.6	98.5	98.4	98.3	98.2	98.1
HMW, SE-HPLC (≤ 5.0%)	1.0	1.1	1.2	1.3	1.3	1.4	1.5
CE-SDS NR purity (≥ 94.0%)	96.5	96.4	96.3	96.2	96.1	95.9	95.8
icIEF main (report)	68	67	66	65	64	63	62
icIEF acidic (≤ 32%)	22	23	24	25	26	27	28
Anti-TL1A potency (80–125%)	102	101	100	100	99	98	97
IL-22R potency (80–125%)	99	99	98	97	97	96	95
Sub-visible ≥ 10 µm (≤ 6000/container)	<500	<500	<500	<600	<700	<800	<900
Polysorbate 80 (report)	0.20	0.20	0.20	0.20	0.19	0.19	0.19
CCIT	Pass	Pass	Pass	Pass	Pass	Pass	Pass

¹ C = clear to slightly opalescent, colourless to pale-yellow solution, essentially free of visible particulates. Sterility and bacterial endotoxins tested at 0 and 24 months: conform.

5.4 Accelerated results (25 °C / 60% RH)

Under accelerated conditions, degradation is measurable and progressive. Increases in HMW species and acidic charge variants are the leading indicators. By 6 months the acidic charge-variant level reaches its acceptance limit — a significant change under the accelerated condition, as anticipated for a refrigerated biologic — while monomer content, size purity, and both potency values remain within their shelf-life acceptance criteria. Consistent with ICH Q5C, the accelerated arm characterizes the degradation profile and the product's response to thermal stress and is not used to assign the shelf life.

Table 5.4-1. DP accelerated stability at 25 °C / 60% RH (mean, n = 3)

Attribute	0 m	1 m	3 m	6 m
Monomer, SE-HPLC (≥ 95.0%)	98.6	98.2	97.6	96.8
HMW, SE-HPLC (≤ 5.0%)	1.0	1.4	2.0	2.6
icIEF acidic (≤ 32%)	22	25	29	33*
Anti-TL1A potency (80–125%)	102	99	96	92
IL-22R potency (80–125%)	99	96	93	90

*The 6-month acidic-variant result marginally exceeds the acceptance limit, constituting a significant change under the accelerated condition (expected for a 5 °C product); this arm characterizes degradation behaviour and is not used to set the shelf life. All other attributes remain within their shelf-life criteria at 6 months.

5.5 Stress results (40 °C / 75% RH)

The stress arm confirms the stability-indicating nature of the panel and defines the failure mode. HMW exceeds the shelf-life limit by ~1 month, monomer falls below 95.0% by ~2–3 months, and both potency values fall below 80% by 3 months, accompanied by a marked rise in acidic charge variants. Fragmentation (CE-SDS reduced) and sub-visible particle counts also increase. The concordance of physicochemical loss with dual-potency decline demonstrates that both the anti-TL1A and IL-22R functional attributes are captured by the release/stability panel.

5.6 Photostability (ICH Q1B, Option 2)

Photostability was assessed on the DP in its primary container both unprotected and in the marketed secondary carton, against dark controls. Directly light-exposed, unprotected DP shows increased oxidation (peptide map), an increase in acidic charge variants (icIEF) and HMW species (SE-HPLC), and a decline in both potency values relative to dark controls. DP protected by the secondary carton shows no significant photo-induced change. Accordingly, TILA-278 DP is photolabile in the primary container, and the label instructs storage in the original carton to protect from light; dark controls confirm the changes are light-attributable and not thermal.

5.7 Trend analysis and shelf-life justification (ICH Q1E)

Long-term data for the three primary DP batches were evaluated per ICH Q1E. For quantitative attributes with a discernible trend (SE-HPLC HMW/monomer, icIEF acidic, relative potency), least-squares regression was performed and batch poolability tested by analysis of covariance (common-slope/common-intercept test at the 0.25 significance level). The three batches were poolable for all evaluated attributes, supporting a single shelf-life estimate.

Because 24 months of real-time data at the long-term condition are available on three representative commercial-scale batches and no attribute reaches its acceptance limit, the 24-month shelf life is directly supported by real-time data and does not rely on extrapolation. The worst-case (one-sided 95% confidence) intercept of the trended attributes with the shelf-life limits lies well beyond 24 months for HMW, monomer, acidic variants, and both potency assays. The accelerated data are consistent with these degradation kinetics and characterize the product's response to thermal stress; the permitted room-temperature excursions are supported by the dedicated in-use study (Section 5.8).

5.8 In-use / temperature-excursion stability

TILA-278 DP is a single-use, single-dose device with no multi-dose in-use phase; the "in-use" considerations for the SC presentation are (a) a single room-temperature storage excursion out of refrigeration, and (b) a short pre-injection warm-up hold. Both were studied directly on finished PFS and AI.

• Single room-temperature storage excursion. Primary batches stored at 5 °C were transferred to 30 °C and tested after a single continuous hold of up to 14 days. All attributes — appearance, SE-HPLC (monomer/HMW), icIEF, both potency assays, sub-visible particles, PS80, and CCIT — remained within shelf-life acceptance criteria, and device function was maintained (Section 5.9). This supports the labelling allowance: the product may be stored at up to 30 °C for a single period of up to 14 days; once removed from refrigeration and stored at room temperature it must not be returned to the refrigerator, and must be discarded if not used within 14 days.
• Pre-injection warm-up hold. To allow the cold product to reach a comfortable injection temperature, a short ambient hold (up to 45 minutes at ≤ 30 °C) was verified with no impact on quality attributes or device delivery.
• Cumulative excursion bracketing. A cumulative/repeated-excursion study bracketing distribution temperature variation confirmed no significant change after the aggregate thermal exposure anticipated across the cold chain.

5.9 Device functional stability (PFS and AI)

Device functionality was evaluated on the assembled PFS and AI held at the long-term condition (5 °C ± 3 °C) and after the room-temperature excursion of Section 5.8, using the delivery-system test panel (3.2.P.2 / 3.2.P.7). All functional attributes met acceptance criteria through the current time points, confirming that neither prolonged refrigeration nor the permitted excursion adversely affects delivery or the device mechanism.

Table 5.9-1. DP device functional stability at 5 °C ± 3 °C (mean, n = 3 batches)

Functional attribute (acceptance)	0 m	12 m	24 m
Break-loose force, PFS (report)	Pass	Pass	Pass
Glide/extrusion force, PFS (within limit)	Pass	Pass	Pass
Needle-shield removal force (within limit)	Pass	Pass	Pass
AI activation force (within limit)	Pass	Pass	Pass
AI injection time (≤ specified s)	Pass	Pass	Pass
Deliverable volume (≥ 1.0 mL, 100 mg)	Pass	Pass	Pass
Cap/needle-cover removal, AI (within limit)	Pass	Pass	Pass
Dose accuracy / end-of-dose click	Pass	Pass	Pass

No trend toward increasing glide or activation force (which could indicate silicone-oil migration or plunger interaction) was observed over the study period.

5.10 DP storage statement and shelf life

Based on the data above, the following are proposed for the TILA-278 DP (both PFS and AI presentations):

• Shelf life: 24 months.
• Storage condition: 5 °C ± 3 °C (2–8 °C). Do not freeze. Store in the original carton to protect from light. Do not shake.
• In-use / excursion allowance: may be stored at up to 30 °C for a single period of up to 14 days; do not return to refrigeration; discard if not used within this period.

The claim is supported by 24 months of real-time long-term data on three commercial-scale batches; accelerated and stress data establishing the degradation profile; the dedicated in-use study establishing tolerance to the permitted temperature excursion; ICH Q1B photostability defining the light-protection requirement; and device functional stability on the assembled presentations.

5.11 Post-approval stability commitment (3.2.P.8.2)

Virtual Biopharma Inc. commits to continue the long-term study on the three primary DP batches through the labelled shelf life and beyond as data accrue, and to place the first three commercial-scale DP batches (one per presentation as applicable) manufactured after approval into the long-term stability program under the approved protocol, with at least one batch per presentation per year thereafter (annual stability). The post-approval protocol retains the long-term (5 °C) and accelerated (25 °C) arms, the full stability-indicating panel, and device functional testing. Confirmed out-of-specification results or adverse trends will be reported per regional requirements, and any change to the storage statement or shelf life will be filed as a post-approval variation supported by the updated data.

6. Overall Conclusions

The DS and DP stability programs for TILA-278 are compliant with ICH Q1A(R2), Q1B, Q1C, Q1D, Q1E, Q5C, and Q6B and are based on three representative commercial-scale batches each. The orthogonal, stability-indicating analytical panel — including two mechanism-reflective potency assays that independently monitor the anti-TL1A antagonist and IL-22R agonist arms — reliably detects the aggregation, fragmentation, charge-variant, and oxidative degradation pathways of the bispecific, as confirmed by forced-degradation and stress studies with maintained mass balance.

The data support:

• a DS retest period of 36 months at ≤ −40 °C (24 months real-time available; study ongoing);
• a DP shelf life of 24 months at 5 °C ± 3 °C (2–8 °C), protected from light, do not freeze, directly supported by real-time data without extrapolation;
• an in-use allowance of up to 30 °C for a single period of up to 14 days for the SC PFS and AI, with maintained product quality and device function.

These conclusions justify the proposed storage conditions, shelf life, in-use conditions, and container-closure/labelling for TILA-278.

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Note: Quantitative CMC stability values presented here that were not directly generated within this portfolio are engineering-representative and standard-conformant for a humanized IgG1 bispecific SC monoclonal antibody; the first occurrence of each such value or claim is marked "." Program identifiers (Virtual Biopharma Inc., TILA-278, Protocol TILA278-201) and the clinical facts referenced are actual to the program.